Not only ________learn a foreign language, but also ______ master it well.

A．must we ; we must

B．must we ; must we

C．we must ;’ we must

D．we must ; must we

鉴别肋骨骨折和挫伤的最佳诊断手法是（）

A.触摸法

B.挤压法

C.叩击法

D.旋转法

E.屈伸法